Going down the highway and all of a sudden the V-10 just shuts off like someone turns the key off.
Have it towed in and later it starts and runs. Take off again and the thing goes about 15 miles and shuts down again. This goes on for two days. I can't get 20 miles down the highway without it shutting down and not starting. Let it set overnight and it will start and run around town without incident, then hit the highway and out it goes.
Everyone feels it's an electrical problem. The computer only shows a code for the fuel pump.
One mechanic feels it's the PCM and the others feel its the fuel pump. Any ideas?

 

it could be a bad pump or pcm. or a bad ground some place.

 

Just got news from the Ford House. The fuel pump was installed and it still shutdown on the test drive after going about 7 miles.
They have ordered another PCM (the old one is under warranty because it's only two weeks old).
Now my question is: Is there another problem that's eating the PCM or did I just get unlucky and get one that's defective. It came from Ford, but I know good and well it's a rebuild.

 

Sorry didn't proof read.

They installed a fuel pump and it only ran 7 miles before failing again.
Now they are putting in a PCM. The one in it is only two weeks old. Question:
Is there something in there eating the PCM or did the replacement one happen to be defective? It came from Ford so it's in warranty.

 

Well you don't know yet if it is the PCM.

I ran into this exact problem with my 99 Dodge Grand Caravan recently. I (personally) replaced the PCM, the crank position sensor & the cam position sensor. I tested every circuit in the coils etc. etc.

Turned out that one of the wires that led to the crank position sensor had melted. Certain bumps and corners would cause it to ground against the tranny and shut off the van. The only way I found it after 2 months of searching is that I pressure washed the engine to get it ready for its push off the cliff and lo and behold the damn thing started. I touched every wire I had every touched while it was running. That bad wire killed the engine.

What I'm saying is Ford "mechanics" will only change parts and will never truly troubleshoot things.

Wait and see if the PCM was the problem. I'm 51% sure that it isn't.

Oh and what did the "fuel pump code" say was wrong?

And one more thing to add to my story... I got the van running after 2 months of pulling my hair out and then the fuggin' $1897.00 tranny went out........

 

Yeah, in this case, it sounds like a thermally induced failure of a sensor somewhere...

While it's very unlikely (unlike a lot of GM cars) that the crank sensor is failing, it sounds like a definite possibility.

However, because you mention a "fuel pump code" that usually means the computer has sensed a lack of voltage going to the fuel pump. I remove the fuse (for the V10), or the plug to the inertia switch (for my 4.6L Cougar), to stop the fuel pump from running when changing the oil. I can crank the motor over until the oil pressure comes up, reconnect the fuse or inertia switch, and I usually get a "fuel pump primary voltage low" or some such.

Sounds like you have ground or other wiring problems, or the fuse is dirty Or inertia switch connector, or the like.

art k.

 

The codes were P0230 and P0231. That was Fuel Pump primry circuit malfunction and fuel pump secondary circuit low.
However, the replacement of the fuel pump still didn't keep it from dying. They then replaced the PCM and I drove home (285 miles) without an incident.
The thing that bothers me is that this PCM was put in the truck on July 13. I then towed a 5th wheel trailer about 900 miles back home and left the truck sitting until last Saturday. That's when we drove about 250 miles and the thing started dying on me again.
Now they replaced the PCM free, but I have no confidence in the truck for long hauls now. No one can give me an answer as to how two PCM's failed in about 2 1/2 weeks.
All Ford will say is that the first one failed due to a computer ship and the second one was defective. I'm just wondering if there is something (like faulty wiring, ground or bad switches) that is intermittenly causing failure.
I don't even know where to go to start looking for the problem, if there is one.
I hate to give up on a good truck that has been maintained and operates great except for electronics in the last three weeks.

 

That's weird, I would check the fuse pump fuse (#19 in my '01 SD) to make sure it's connections are good, and isn't there a fuel pump relay somewhere? If that relay is failing, it could possibly trigger those two codes.

Especially if the computer is logging a primary and secondary failure.

Think about it. The coil in the relay can be detected by the computer as a current drain. If the coil (or connections) are faulty, the computer will see it and log a primary circuit failure, and of course, because the relay isn't firing, it will also log a secondary circuit low.

The thing is, I'm not sure if there is a relay ... I'll have to check my CD service manual, but it's out in the garage and I'm in the basement.

If I remember, I'll try to get out there today to look for you.

It could also be a bad ground coming loose, which has been known to happen.

art k.

 

Stay with me on this guys. I'm checking out everything you say. I don't want to lose confidence in a good truck.
I took it to my local Ford house and they are going to start looking at some things for me. They agree with you guys. They say it's extremely rare that they lose a computer on a V-10 unless it's been in lightining. They loose them on diesels, but not the V-10.
They don't rule out that the first PCM put in might have been defective.
They have checked the main grounds inside the kick panel on the driver's side and they looked good. They did find a vacuum leak at the throttle head that the other two Ford houses didn't catch. The hose had a tear about 1 1/2 inches long in it. The guy said this wouldn't have caused it to fall on it's face, but it will fix some rough idling
They are going to keep it the whole week and drive it around to see if it will send some pending codes. these fellows are on our side. They like the V-10. They say they rarely have problems with them.

 

Sounds like you got a gem of a dealer...

Cool...

art k.

 

I lost the PCM in my truck in the first 15 min. of driving (at least that's what they tell me) It didn't die all together but gave me random missfires, alot of them. Ford replaced the PCM, that didn't work until they reflashed it with current updates. Still doesn't make sense to me, but what do I know.

 

thanks again for your input. I just got back from the local Ford house and all they could find was a tear in the vacuum hose on the throttle body.
They checked the main grounds and still haven't found anything. I guess I will have to drive it and see if anything happens again.
Their best guess was that the first time I had trouble was the tr sensor going out and causing the faulty shifting. Something happened when repairing that and the PCM got ruined. The 2nd time they believe my fuel pump went out and the PCM replacement was faulty. They are not sure of any of this but it's their best guess with the thing running fine and showing no codes.
I have a whole list of electrical possible causes, but I have no idea of how to check them or even find them. Any advice on how to check for fuseable links or sensor wiring is welcomed.
I think I have gremlins.

 

The two things to check if it does it again - fuel pressure, and spark.

Without a spare COP and plug, I'm not sure how to tell you to verify that without taking one out and seeing if it sparks. If you had a spare COP, you could disconnect the harness from one, connect it to the spare COP, throw a plug in it and see if you get a spark (with the plug grounded to the motor of course).

The fuel pressure, you'd need a guage hooked to the fuel rail.

art k.

 

My truck has shut off 2 times, once was at a really bad time and that happend to be the first time and I was really shocked!!!!!! It was in a hard turn and with my boat in tow.... well got it arround and it then started rigt up... second time was last week and going straight down the road at about 25 mph it shut off... its really hard to tell when it shuts off I olny know because of the loss of P/S and P/B. Its so quiet that you dont miss that its not running....

I havent been to the dealer yet.. figured its a hard find since I cant make it do it... Im not sure if there are any codes no lights came up.

 

This reminds me of my '96 T-bird 4.6L with a Superchips installed.

It would shutdown for no reason, never log a code, etc.

Turned out the computer was locking up and resetting... Superchips warranteed the chip, and it's been fine since (ask my sister).

Sounds like the computer is freezing, but don't rely on my assessment and go spending big $'s.

art k.